Catalyst for preparation of biaryl compounds

Abstract

A method for the preparation of biaryl compounds is disclosed which comprises contacting an aryl halide with a tertiary-alkyl organometallic reagent (or the precursor components thereof) in the presence of a catalyst comprising a nickel compound and a coordinating ligand under conditions suitable for the formation of biaryl compound. In an alternate embodiment of the present invention, nickel(O) compounds are prepared from nickel(II) compounds by contacting a nickel(II) compound with a combination of an organophosphine and a bidentate nitrogen-containing coordinating ligand, and a tertiary-alkyl organometallic reagent (or the precursor components thereof) in an aprotic, non-polar, ether-containing solvent system for a time and under conditions suitable for the formation of nickel(0) compound.

I claim: 
     
       1. A method for the generation of nickel (0) species from nickel (II) compounds comprising contacting a nickel (II) compound with (i) an organophosphine ligand of the formula PR" 3  or R" 2  P-Z-PR" 2  wherein each R" is independently selected from the group consisting of alkyl, aryl and alkaryl radicals having up to 20 carbon atoms and -Z- is an alkylene, alkenylene, or arylene radical;   (ii) a bidentate ligand selected from the group consisting of 2,2'-bipyridine, 2-picolinic acid, ethylenediamine tetraacetic acid, N,N,N',N'-tetramethylethylenediamine, 1,10-phenanthroline, N,N'-bis(salicylidene)ethylenediamine, and polyvinyl pyridine;   (iii) a tertiary-alkyl organometallic compound of the structure: ##STR9##  wherein each R' is independently selected from the group consisting of H and alkyl groups having in the range of 1 up to 20 carbon atoms, and M is selected from the group consisting of Li, Na, K, and MgX, wherein X is a halogen; wherein said contacting is carried out in a substantially anhydrous, non-polar, ethereal solvent system, optionally containing up to 95 volume percent of an aliphatic or aromatic hydrocarbon diluent at a temperature in the range of about 0° up to 100° C. for a time in the range of about 0.5 up to 24 hours.     
     
     
       2. A method for the generation of nickel (0) species from nickel (II) compounds comprising contacting a nickel (II) compound with (i) an organophosphine ligand of the formula PR" 3  or R" 2  P-Z-PR" 2  wherein each R" is independently selected from the group consisting of alkyl, aryl and alkaryl radicals having up to 20 carbon atoms and -Z- is an alkylene, alkenylene, or arylene radical;   (ii) a bidentate ligand selected from the group consisting of 2,2'-bipyridine, 2-picolinic acid, ethylenediamine tetraacetic acid, N,N,N',N'-tetramethylethylenediamine, 1,10-phenanthroline, N,N'-bis(salicylidene)ethylenediamine, and polyvinyl pyridine; and   (iii) a tertiary-alkyl halide of the structure: ##STR10##  wherein each R' is independently selected from the group consisting of H and alkyl groups having in the range of 1 up to 20 carbon atoms, and X is a halogen; and   (iv) a metal, M, selected from the groups consisting of Li, Na, K or Mg; wherein said contacting is carried out in a substantially anhydrous, non-polar, ethereal solvent system, optionally containing up to 95 volume percent of an aliphatic or aromatic hydrocarbon diluent at a temperature in the range of about 0° up to 100° C. for a time in the range of about 0.5 up to 24 hours.     
     
     
       3. A process in accordance with claim 1 wherein said nickel (II) compound is selected from the group consisting of nickel acetylacetonate, nickel sulfate, nickel nitrate, nickel oxide, the nickel hydroxides, the nickel halides, and the nickel carboxylates. 
     
     
       4. A process in accordance with claim 1 wherein said organophosphine ligand is selected from the group consisting of triphenylphosphine, tricyclohexylphosphine, tribenzylphosphine, diphenylbutylphosphine, 1,4-bis(diphenylphosphino)butane, 1,6-bis-(diphenylphosphino)hexane, 1,1'-bis(diphenylphosphino)ferrocene, 2,2'-bis(diphenylphosphinomethyl)-1,1'-biphenyl, bis(α,α'-diphenylphosphino)-o-xylene, and 1,2-bis(diphenylphosphino)ethane. 
     
     
       5. A process in accordance with claim 1 wherein said tertiary-alkyl organometallic compound is selected from the group consisting of t-butylmagnesium chloride, t-butyl lithium, t-butyl sodium, t-butyl potassium, t-amylmagnesium chloride, t-amyl lithium, t-amyl sodium, and t-amyl potassium. 
     
     
       6. A process in accordance with claim 1, wherein the molar ratio of tertiary-alkyl organometallic compound to nickel falls in the range of about 0.2:1 up to 5:1. 
     
     
       7. A process in accordance with claim 1 wherein the molar ratio of nitrogen-containing ligand to nickel falls in the range of about 0.5:1 up to 20:1. 
     
     
       8. A process in accordance with claim 1 wherein the molar ratio of organophosphine to nickel falls in the range of about 0.3:1 up to 30:1. 
     
     
       9. A process in accordance with claim 1 wherein said solvent system comprises at least one ether selected from the group consisting of dimethyl ether, tetrahydrofuran, diisopropyl ether, dibutyl ether, ethylene glycol dimethyl ether, dioxane, and methyl t-butyl ether, and, optionally, up to 95 volume % of an aliphatic or aromatic hydrocarbon selected from the group consisting of benzene, toluene, xylene, hexane, octane, cyclohexane, and mixtures of any two or more thereof.